1) Field of the Invention
The present invention relates generally to agricultural implements and, more specifically, to a depth control adjustment for cylinder operated lift system on an implement.
2) Related Art
Hydraulically operated lift structures on an agricultural implement often include hydraulic or mechanical stops to adjust position of the implements. For example, on tillage and seeding equipment frames, hydraulic depth controls of the type shown and described in U.S. Pat. Nos. 5,427,184 and 5,366,024 provide adjustable hydraulically operated down stops but require relatively complex linkage arrangements. Series cylinder hydraulic systems are also commonly utilized, but cylinder or other system leakage can adversely affect the depth setting in systems which require cylinder pressure to hold a preselected depth setting. Various mechanical stop systems, such as cylinder collars or donuts placed over the rod of a hydraulic cylinder provide a solid mechanical stop, and the number or size of the collars can be changed to adjust implement position. However, such adjustments are time-consuming, particularly if the cylinder is located in a position that is hard to access. Small changes in implement position are often difficult to achieve with many of the previously available, and individual adjusting components usually require a separate storage area and are easily lost or misplaced. Heretofore, providing a relatively simple and inexpensive mechanical stop that is reliable and yet easy to adjust for different implement positions has been a continuing problem.